Your latest Bios is 2603 available here: https://www.asus.com/au/Motherboards/M5A97_R20/HelpDesk_Download/
Use your EZ Flash 2 utility in Bios.
Download the Bios file from support to an empty, FAT32 formatted. single partition USB stick.
Once done insert the USB into a suitable USB port and check that the Bios file is named M5A97R.CAP